Validate the request. If a group ID is supplied, the group object will be fetched and validated against the current conference. If, additionally, the user ID is supplied, the user and membership objects will be validated and fetched.

Parameters:

$groupId

int optional

$userId

int optional

$fetchMembership

boolean Whether or not to fetch membership object as last element of return array, redirecting if it doesn't exist; default false

Returns:

array [$conference] iff $groupId is null, [$conference, $group] iff $userId is null and $groupId is supplied, and [$conference, $group, $user] iff $userId and $groupId are both supplied. $fetchMembership===true will append membership info to the last case, redirecting if it doesn't exist.